Group of Motor Vehicles

ABSTRACT

In a group of motor vehicles of one vehicle type with three different drive concepts (“internal combustion drive”, “electric drive” or “hybrid drive”), the architecture of the motor vehicles having an electric drive is used to produce the motor vehicles of all three drive concepts. Irrespective of the drive concept, two variations of an elevated floor panel assembly are used, each of the two floor panel assemblies having a frame-like supporting structure. The first floor panel assembly is provided for the vehicles having an electric drive. Here, the battery is used as a supporting structural component and significantly takes over the reinforcement of the frame-like floor panel assembly. A second floor panel assembly is provided for the vehicles having a hybrid drive and having an internal combustion drive. In the second floor panel assembly, at least one reinforcing additional component is provided in order to provide sufficient structural rigidity.

BACKGROUND AND SUMMARY

The invention relates to a motor vehicle group of a motor vehicle type.

In conjunction with the present invention, the following definitions are significant.

“Vehicle type:” In colloquial usage also referred to as “vehicle model,” i.e., motor vehicles of which the external appearance (irrespective of the drive concept) is substantially identical. As an example of this, the vehicle type with the model designation “BMW 2 Series Active Tourer” from the applicant is mentioned. At the time of filing of the present patent application, this vehicle type was available in several variants with internal combustion engine as well as in a variant with hybrid drive (“BMW 225xe iPerformance Active Tourer”), wherein the variant with hybrid drive has a substantially identical external appearance to the motor vehicles with internal combustion engine.

“Motor vehicle group:” Entirety of motor vehicles of one vehicle type, regardless of the drive concept.

“Drive concepts” are “internal combustion engine” (or “combustion drive”), “electric motor” (or “electric drive”) and “hybrid drive”, hereinafter also referred to in this order as “ICE” (Internal Combustion Engine), “BEV” (Battery Electric Vehicle) and “HEV” (“Hybrid Electric Vehicle”), respectively. “HEV” (Hybrid Electric Vehicle) also includes “PHEV” (“Plug-in Hybrid Electric Vehicle”).

“Internal combustion engine:” Combustion engine powered by a fuel (gasoline, diesel, hydrogen, etc.) to drive a motor vehicle.

“Electric motor” means an electric machine for driving a motor vehicle.

“Battery:” Storage device for storing electrical energy to feed the electric motor, i.e., “drive battery”. The term “high-voltage storage device” is also frequently used.

“Hybrid drive:” Combination of an internal combustion engine and at least one electric motor as prime movers for driving a motor vehicle. The variant of the hybrid drive with the possibility of being able to charge the battery of the motor vehicle with electrical energy from outside the motor vehicle is usually referred to as a “Plug-in Hybrid Electric Vehicle” (PHEV). The variant of the hybrid drive without the possibility of external charging is usually referred to as a “Hybrid Electric Vehicle” (HEV).

“Body-in-white structure:” Combination of the components that form the load-bearing structure of the motor vehicle. The components are, for example, interconnected sheet metal components. Also included herein is a combination of sheet metal or cast metal components. The interconnected sheet metal components may be sheets of different materials, for example steel and aluminum.

“Floor panel assembly:” Components of the body-in-white structure that in their entirety form the lower region of the passenger compartment of the motor vehicle.

“Front end assembly:” Components of the body-in-white structure that in their entirety form the load-bearing region in the longitudinal direction of the vehicle, including a bulkhead. These include in particular the front longitudinal members, which together with the front axle support a prime mover and dissipate a significant amount of crash energy in the event of a frontal collision.

“Luggage compartment floor assembly:” Components of the body-in-white structure that in their entirety cover the region in the longitudinal direction of the vehicle from a “front cross member rear axle” to a rear end member. In the transverse direction of the vehicle, the luggage compartment floor assembly extends between a right and a left wheel arch and includes the rear longitudinal members.

It is generally known that manufacturers of motor vehicles use uniform components and standardized interfaces for the body-in-white structure as far as possible in order to increase the efficiency of the production process of their motor vehicles, for example to produce body variants of a vehicle, i.e., for example, in addition to a sedan, a body variant of the station wagon and/or coupe and/or convertible type, etc.

Furthermore, also for vehicles belonging to different “vehicle classes” or “vehicle segments”, manufacturers of motor vehicles use uniform components for the body-in-white structure, for example for mid-range and upper mid-range motor vehicles. This use of uniform components is known among some manufacturers of motor vehicles, for example, under the term “platform strategy”.

In this context, it is known from WO 2016/192921 A1, for the production of motor vehicles from different vehicle classes, to provide “front end modules” and “passenger compartment modules”, wherein the modules can be combined without restriction and in this way the motor vehicles of the different vehicle classes can be formed. Here, the front end modules have different engine mount spacings and the passenger compartment modules have different front seat spacings.

In addition to vehicles with an internal combustion engine (“combustion drive”), manufacturers of motor vehicles are increasingly offering vehicles that have an electric motor as the drive unit (“electric drive”) and/or vehicles that have a combination of an internal combustion engine and an electric motor (“hybrid drive”). Thus, there are motor vehicles with two or three different drive concepts of one vehicle type. The three drive concepts are referred to below as “combustion drive”, “electric drive” and “hybrid drive”.

In this context, it is particularly interesting from an economic point of view, which the applicant has made, to be able to manufacture the motor vehicles with the above-mentioned three drive concepts with components for the body-in-white structure which are as uniform as possible. Since it is not possible to foresee how demand will be divided among the three drive concepts within a vehicle type, the greatest possible flexibility in production must be sought in order to be able to respond to changes in demand for the motor vehicles with the different drive concepts as the situation demands.

It is generally known to provide motor vehicles with “electric drive” with a battery arranged over a large area in the region of the vehicle floor. For this purpose, the floor region of these motor vehicles is arranged higher compared to a motor vehicle of the same vehicle type with “combustion drive”, preferably while maintaining the same position of the seats in the motor vehicle, i.e. with an identical H point (hip point). The identical H point makes it possible for the motor vehicles of one vehicle type to have the same layout of the interior, including the arrangement of the pedals and other controls. In addition, the headroom dimensions are the same and the equipment components can also be kept substantially the same. Exceptions to this are, for example, floor coverings, cable harnesses, rear air ducts, etc.

Also known from DE102008055738A1 is a modular system for building a motor vehicle body in which modules from at least two module groups can be freely combined and selected. In particular, it is intended that a number of main floor modules and a number of front end and rear end modules can be freely combined so that, for example, different drive concepts or floor heights do not prevent the main floor from being freely combined with the front end and rear end.

The object of the invention is to provide a new approach for the production of body-in-white structures for motor vehicles of a vehicle type with the above-mentioned three different drive concepts, while using uniform components for the body-in-white structure as far as possible. Furthermore, the invention is intended to provide a new approach for the production of body-in-white structures for motor vehicles of a vehicle type with the above-mentioned three different drive concepts which makes it possible to accommodate the largest battery possible in the case of the motor vehicles with “hybrid drive”, while also using uniform components for the body-in-white structure as far as possible in the case of the motor vehicles with “combustion drive”.

This object is achieved by a motor vehicle group having the features of the indepedent claims.

The core concept of the invention is to start from the “architecture” of the motor vehicles with “electric drive” for the production of the motor vehicles of all three drive concepts.

Against the background of the expected increasing electrification of motor vehicles and the resulting reduction in the number of new “combustion drive” motor vehicles coming onto the market, the invention lays the foundation for a new vehicle architecture and for derivations from this to the “electric drive”. With this fundamental reversal of the previously prevailing architectural approach, the body-in-white structure of a motor vehicle with “electric drive” becomes “the new norm”.

This new architectural approach uses the principle of a “raised” floor panel assembly of the motor vehicles with “electric drive” for all drive concepts of the motor vehicles of one vehicle type.

The “raised” floor panel assembly is distinguished in that, due to the “raising” on the underside of the floor panel assembly, installation space is provided for accommodating a battery which is not available in a “conventional motor vehicle” with “combustion drive”. This is realized in that the front longitudinal members of the front body assembly end in the transition region between the front body assembly and the floor panel assembly, i.e. in the region of a bulkhead. In conjunction with the present invention, this means that the front longitudinal members are not continued on the underside of the floor panel assembly facing a roadway, as is the case in conventional motor vehicles, in order to achieve a uniform transfer of force from the front end assembly to the floor panel assembly. In other words, in the “raised” floor panel assembly, the front cross member and its connecting region with the front longitudinal members are configured so that there is no overlap of this connecting region with the underside of the floor panel assembly.

The elimination of longitudinal member structures on the underside of the floor panel assembly, in conjunction with a “raising” of the floor panel assembly compared with conventional motor vehicles, creates an installation space that is suitable for the arrangement of a large-area battery for both “electric drive” and “hybrid drive” motor vehicles. This allows a fundamentally different extended dimension with regard to the storage size of the battery. This is of fundamental importance, particularly with regard to the “electric range” of motor vehicles with “hybrid drive” of 80 to 100 (or more) kilometers that will be required in the future, since future legislative regulation will only grant financial or other usage rules (such as entry or parking permits) at the range specified above.

In accordance with the invention, two different floor panel assemblies are provided which have an identical height position (vertical direction Z) in their installation positions in the motor vehicle.

Here, a first floor panel assembly is provided for the “electric drive” motor vehicles.

In addition, in accordance with the invention, a “raised” second floor panel assembly is used not only in the “hybrid drive” motor vehicles but also in the “combustion drive” motor vehicles. This results in a decisive advantage in that the front end assembly adjoining the front in the direction of travel and/or the luggage compartment floor assembly adjoining the rear in the direction of travel of the motor vehicles of a vehicle type can be uniformly designed and/or connected to the two floor panel assemblies with a uniform interface, regardless of the drive concept.

The two floor panel assemblies have a frame-like supporting structure. They consist of two side longitudinal members, a front and a rear cross member, and at least one further (middle) cross member. In principle, further components can be arranged on this supporting structure with longitudinal and cross members, for example components which serve to fasten and connect components of the motor vehicle, such as seats, center consoles, side frames with doors (on the inside of the vehicle) and batteries, containers for fuel and/or other media, components of exhaust systems (on the outside of the vehicle). In both floor panel assemblies, the longitudinal and cross members form a ladder-like frame structure with at least one front and one rear frame portion. In this respect, the two floor panel assemblies are embodied as identical parts, i.e. as defined in more detail below, they are produced on one production line (or on several similar production lines), irrespective of their subsequent use as first or second floor panel assemblies.

The frame portions of the floor panel assemblies each define window-like cutouts which are at least partially closed by at least one flat closure component (“floor panel”) and thus separate the vehicle interior from the vehicle exterior. Such a flat closure component is absolutely necessary, for example, in the region of a fuel tank arranged underneath, since fuel tanks may only be arranged in the vehicle exterior. The flat closure components are not in themselves designed to stiffen the floor panel assembly to an extent required for adequate rigidity of the body-in-white structure. The stiffness requirements are determined by the static and dynamic loads when the motor vehicle is stationary and in operation, including the absorption of crash forces, ensuring vibration comfort and stable driving dynamics, etc.

In accordance with the invention, the difference between the two floor panel assemblies is that the frame portions in the first floor panel assembly are stiffened by at least one battery so that the stiffness requirements described above are fully met, while at least one frame portion of the second floor panel assembly is provided with at least one stiffening add-on component.

The two floor panel assemblies can thus be manufactured in a uniform manner, wherein only the second floor panel assembly is followed by an additional manufacturing step, namely the attachment of at least one stiffening add-on component. The stiffening add-on component can be, for example, a flat component or an elongate or cross-shaped strut-like component. Strut-like stiffening add-on components can be formed, for example, by extruded profiles. In the second floor panel assembly, the stiffening add-on component serves to produce equivalent stiffness to that of the first floor panel assembly, in which the stiffness requirements are significantly achieved by incorporating the at least one battery into the body-in-white structure, wherein the at least one battery acts as a load-bearing structural component.

The stiffening add-on component is characterized in that it significantly stiffens at least one frame portion. This distinguishes the stiffening add-on component from, for example, small-area reinforcing parts which may be arranged in corner areas or “intersection areas” of the frame-shaped floor panel assembly. Such reinforcing parts are provided, in particular, on the front cross member to manage the transfer of forces from the front longitudinal members of the front end assembly to the floor panel assembly. Another characteristic of the stiffening add-on components is their clear assignment to the floor panel assembly for the purpose of stiffening the latter. In other words, the stiffening add-on components have no other fundamental task than stiffening at least one frame portion instead of at least one battery.

The stiffening add-on component is preferably connected to the longitudinal and/or cross members by bolting. For this purpose, bolting points can be used which are provided in the motor vehicle with “electric drive” for connecting at least one battery.

The flat closure components described above make only an insignificant contribution to stiffening the frame portions of the two floor panel assemblies. For reasons of separation of the vehicle interior from the vehicle exterior, the flat closure components are also present (at least in part) in the first floor panel assembly.

The at least one stiffening add-on component is arranged in the frame portion(s) of a second floor panel assembly which is/are not stiffened by a battery having a rigid battery housing as a load-bearing structural component. Thus, a stiffening add-on component is naturally required in the region of an unoccupied structural space below the second floor panel assembly. Likewise, a stiffening add-on component is required, for example, in the region of a fuel tank arranged below the second floor panel assembly or of a housing for accommodating components of the motor vehicle, since neither a fuel tank nor such a housing normally have sufficient structural rigidity.

As already mentioned above, another characteristic of the two floor panel assemblies is that they are uniformly designed at their connection regions to a front end assembly and/or a luggage compartment floor assembly, thus enabling the connection of uniform front end assemblies and/or uniform luggage compartment floor assemblies.

The core concept described above of a fundamentally “raised” floor panel assembly for motor vehicles with all three drive concepts, including those with “combustion drive”, is offered in view of the comparatively low proportion of “combustion drive” expected in the future among the three drive concepts in a vehicle type. This means that a floor panel assembly of uniform height can be used for all motor vehicles of a given vehicle type, irrespective of the drive concept, resulting in significant potential savings in the production of the motor vehicles. In return, it can be accepted in the design of “combustion drive” motor vehicles that an installation space, available in principle, below the floor panel assembly is not used for the benefit of a passenger compartment that is larger in the upright direction Z of the motor vehicle.

This allows the different drive concepts to be provided in a new type of vehicle architecture using a minimum number of body assemblies.

On the one hand, the invention allows at least one battery to be arranged underneath the floor panel assembly in “hybrid drive” motor vehicles, the battery being “flat”, i.e. formed in the manner of a “panel”, with a significantly greater extent in the longitudinal and transverse directions of the vehicle than in the vertical direction. This distinguishes the motor vehicles according to the invention from motor vehicles with “hybrid drive” according to the prior art, in which the battery is accommodated in the limited installation space under the rear seats or in the region of the luggage compartment. On the other hand, the floor panel assembly is also used as an identical part in the “combustion drive” motor vehicles.

The “raised” floor panel assembly may be designed to accept batteries of different sizes and/or shapes on its underside. The batteries may differ in size externally, by correspondingly different dimensions. Likewise, “batteries of different sizes” may also differ in their storage capacity, i.e., in the amount of charge that can be drawn.

The two floor panel assemblies are “identical parts”, regardless of which of the three different motor vehicles the particular floor panel assembly is used on. A characteristic feature of these “identical parts” is that all copies of the two floor panel assemblies are produced with the same deep-drawing die or with the same set of deep-drawing dies.

In the context of the present invention, “the same deep-drawing tool” is to be equated with “the same casting tool”, as is a combination of the two tools mentioned. For reasons of linguistic simplification, reference is made in the following predominantly only to “deep drawing dies”. The manufacture of body-in-white components by deep drawing is the most commonly used manufacturing method.

The term “identical part” therefore covers those components for the body-in-white structure which are produced with the same deep-drawing die. Following manufacture in the pressing plant, the length of these “identical parts” can be changed, for example, by shortening or lengthening. When shortening by cutting to length, for example, a longitudinal member or a deep-drawn sheet metal portion which is used across the board for motor vehicles of different drive concepts is shortened by being trimmed at one of its end portions, depending on the drive concept. Alternatively, the longitudinal member or sheet portion can also be lengthened by attaching an extension piece depending on the drive concept, by riveting, welding, bolting, bonding, etc. These length adjustments, by cutting to length (trimming) or by lengthening (joining), are production steps which are carried out as a subsequent measure on “identical parts” previously manufactured with a uniform deep-drawing die, so that only comparatively low labor and tooling costs are incurred for these subsequent measures.

Deep-drawn sheet components are, for example, floor panels, longitudinal members, etc. The sheet material can be homogeneous along its surface extent or, for example, can be formed by a so-called “taylored blank”.

In terms of the floor panel assembly, “scaling” is possible, for example, by trimming the floor panel assembly in the longitudinal direction of the motor vehicle in order to realize wheelbases of different sizes.

Furthermore, the term “identical part” includes body-in-white components that are produced with the same casting tool. The advantage of cast components lies, among other things, in the wide range of possibilities for integrating functions, add-on parts, connection regions, etc. For example, suspension strut mounts, mounts for front axle carriers, or front longitudinal members (engine mounts) can be advantageously formed by cast components.

In principle, both floor panel assemblies formed as “identical parts” can have different hole patterns for connecting the “identical part” to the subsequent body-in-white and/or to add-on parts, by punching, drilling, etc. The “identical parts” can also have different hole patterns for connecting the “identical part” to the subsequent body-in-white and/or to add-on parts. However, the decisive factor for the “identical parts” is that no further significant forming changes take place after manufacture in the same deep-drawing die. In particular, common parts are characterized by uniform connection regions to adjacent assemblies. The use of a uniform deep-drawing die across the different drive concepts significantly reduces the investment costs for the production equipment. Different hole patterns are required, for example, when manufacturing motor vehicles in different country versions as so-called “left-hand drive” or “right-hand drive” or with different exhaust systems.

Furthermore, a plurality of fastening points (preferably bolting points) can be provided on the identical parts, wherein at least one motor vehicle with a particular drive concept makes use of only some of the fastening points.

Of course, “identical parts” can also be at least partially identical components.

The identical parts can be supplemented in the individual motor vehicles or drive concepts by specific “adaptation parts”, such as different specific yokes in the floor region to accommodate an exhaust system or different brackets on a same front end and/or bulkhead region.

The invention relates to motor vehicles with front-wheel drive or with all-wheel drive according to the following system: The front end assembly is configured exclusively to accommodate a transversely mounted internal combustion engine with drive of the front wheels or to accommodate an electric motor, naturally also with drive of the front wheels. By eliminating the option of a longitudinal engine with a transmission projecting into a floor panel assembly and a drive shaft extending under the floor panel assembly to a driven rear axle, the floor panel assemblies described above in accordance with the invention and formed as identical parts can be used. Although these floor panel assemblies according to the invention are arranged higher than a floor panel assembly for a motor vehicle with “combustion drive” according to the prior art and thus somewhat restrict the available space in the passenger compartment, on the other hand they provide installation space below the floor panel assembly which can be used almost completely for accommodating the battery (batteries). In the case of an exhaust line leading to the rear of the vehicle, a free space must be provided in the region of the center of the vehicle, so that in this design batteries, fuel tanks, housings for components of the motor vehicle etc. cannot extend over the entire width of the vehicle but are designed, for example, with the width of only one half of the vehicle.

The front-wheel drive by an internal combustion engine and/or by an electric motor can be supplemented by an electric motor on the rear axle to form a so-called “road-coupled all-wheel drive”. This results in the following possible constellations:

-   -   front wheel drive exclusively by an internal combustion engine         (“combustion drive”)     -   front wheel drive exclusively by an electric motor (“electric         drive”)     -   front wheel drive by the combination of an internal combustion         engine with an electric motor, preferably in a structural unit,         for example by integrating the electric motor in a transmission         flanged to the internal combustion engine (“hybrid drive”)     -   all-wheel drive with an internal combustion engine for driving         the front wheels and an electric motor for driving the rear         wheels (“hybrid drive”)     -   all-wheel drive with a combination of an internal combustion         engine with an electric motor, preferably as a structural unit,         for example by integrating the electric motor in a transmission         flanged to the internal combustion engine for driving the front         wheels and with an electric motor for driving the rear wheels         (“hybrid drive”)     -   all-wheel drive with an electric motor for driving the front         wheels and an electric motor for driving the rear wheels         (“electric drive”).

Of course, instead of a single electric motor on the front axle and/or on the rear axle, several electric motors, preferably two electric motors per axle, can also be provided, preferably near the wheels.

The motor vehicle group according to the invention is not designed to represent motor vehicles with “standard drive”, i.e. motor vehicles with longitudinally mounted front engine with flanged transmission and drive of the rear wheels via a drive shaft, including the extension to all-wheel drive via a transfer case for driving the front wheels.

The design according to the invention does involve compromises with regard to the package of motor vehicles with “combustion drive”. Nevertheless, based on the considerations outlined above with regard to the proportions of the individual drive concepts in a vehicle type, it may make sense, for economic reasons, to reduce the number of floor panel assemblies to two floor panel assemblies formed as identical parts (scenario with a low sales proportion of “combustion drive” motor vehicles within a vehicle type).

Particularly in the case of small displacement combustion engines, for example in the course of downsizing with regard to the number of cylinders and/or power output due to stricter CO2 regulations, combustion engines installed in the transverse direction of the vehicle may be increasingly used in the future.

As a result of the invention, a space is available on the underside of the first floor panel assembly in motor vehicles with “combustion drive” for arranging a housing for components of the motor vehicle. This housing can, for example, accommodate components that are specific to a motor vehicle with “combustion drive”, such as an SCR tank, an activated carbon filter, a 48-volt battery, components of the air supply system, etc.

The housing therefore has the function of a “module tray”. Instead of being accommodated in a housing, however, the components can also be arranged on their own, without a housing or attached to a common frame, on the underside of the floor panel assembly.

In particular, advantages arise in motor vehicles with “hybrid drive” or with “combustion drive” if an internal combustion engine installed in the transverse direction of the motor vehicle is combined with an exhaust system ending in the front region of the passenger compartment. In such an exhaust system, the at least one rear muffler is arranged in the region under the passenger compartment, in the front region of the floor panel assembly. This means that more installation space is available underneath the floor panel assembly in the center and/or rear portion of the motor vehicle, for example for accommodating a comparatively large fuel tank in the region of the so-called heel panel. In this constellation, a single battery extending over a substantial part of the vehicle width can be provided in a motor vehicle with “hybrid drive”, since there is neither a drive shaft for the rear wheels nor an exhaust line extending into the rear of the vehicle. Similarly, in this constellation, a motor vehicle with “combustion drive” can be fitted with a continuous housing extending over a substantial part of the vehicle width. The elimination of the exhaust line and rear muffler in the region of the luggage compartment floor assembly also makes more volume available in the luggage compartment and/or below the luggage compartment floor assembly.

In an embodiment of the invention, at least one luggage compartment floor assembly is provided, the front region of which is configured for connection to the rear region of the floor panel assemblies formed as identical parts. The at least one luggage compartment floor assembly is formed in such a way that sufficient installation space is available in its front region below the luggage compartment floor assembly to accommodate, for example, an electric motor.

Preferably, a uniform luggage compartment floor assembly is provided.

However, it is also possible to provide two or more luggage compartment floor assemblies, in each case provided that the front region of the luggage compartment floor assemblies is of uniform design for connection to the floor panel assemblies. The potentially different design of the luggage compartment floor assemblies can be adapted to the particular drive concept of the motor vehicle in order to optimize the usable luggage compartment volume in their middle and/or rear region, for example depending on whether an electric motor (with or without inverter), an exhaust system (in particular a rear muffler), an activated carbon filter, an SCR tank, etc. is arranged below the particular luggage compartment floor assembly.

In an advantageous embodiment of the invention, the fuel tank is arranged uniformly both in the motor vehicles with “combustion drive” and in the motor vehicles with “hybrid drive”, in a region in front of the rear axle, in the region under rear seats of the motor vehicle, and over a large area under the rear part of the floor panel assembly. Preferably, a uniform fuel filler system is provided for the motor vehicles with these two drive concepts, for example with the same filler pipes.

However, the fuel tanks for motor vehicles with “combustion drive” on the one hand and with “hybrid drive” on the other are embodied fundamentally differently. In the case of motor vehicles with “hybrid drive”, driving in purely electric mode and thus the absence of fuel withdrawal results in a pressure build-up in the fuel tank, which necessitates the use of a pressure tank, preferably made of steel, in these motor vehicles.

A further aspect of the invention is explained below, which consists in the fact that a uniform “body” (i.e. a uniform body-in-white structure with uniform outer skin components) can be used for the motor vehicles with the different drive concepts. In order to be able to realize such a uniform body, a “lifting” of the motor vehicle (starting from a conventional motor vehicle with “combustion drive” or a motor vehicle with “hybrid drive” according to the prior art) is necessary for all motor vehicles of one vehicle type, in addition to further measures (such as adapting the “silhouette”, larger wheels, etc.), which are explained in greater detail below.

This “raising” is only technically necessary for “flat” motor vehicles, such as sedans, motor vehicles of the station wagon type, coupes, convertibles etc. In the case of “tall” motor vehicles, i.e. motor vehicles with a comparatively high seating arrangement, such as “sport utility vehicles” SUVs or “sport activity vehicles” SAVs, “raising” may not be necessary.

In the case of motor vehicles with “electric drive” and in the case of motor vehicles derived therefrom with “hybrid drive”, the “raising” of the floor panel assembly ensures that sufficient ground clearance is guaranteed in the case of motor vehicles with these two drive concepts which have at least one battery arranged on the underside of the floor panel assembly. In the case of “combustion drive” motor vehicles likewise derived from the “electric drive” motor vehicles, this raising is not technically necessary, but is carried out in accordance with the invention for the economic considerations described above.

This sufficient ground clearance is achieved, among other things, by the fact that the motor vehicles of all three drive concepts according to the invention have “wheel sizes” (meaning the diameter of a wheel/tire combination) at the front and/or rear axle which have an increased diameter compared with a comparable motor vehicle with (only) a “combustion drive”. In addition to “raising” the floor panel assembly, this also takes account of the higher wheel load required for “electric drive” and “hybrid drive” motor vehicles due to the weight of the battery (or batteries). A side effect of this, however, is that in the motor vehicle group according to the invention, the motor vehicles with “combustion drive” also have larger dimensioned wheels than would be necessary for purely technical reasons. The reason for this is the realization of a uniform outer skin with uniform wheel cutouts and “matching” wheels for all motor vehicles in the motor vehicle group according to the invention, regardless of the drive concept.

A decisive feature of the invention is that the two floor panel assemblies each have uniform connection regions (“interfaces”) to a bodyshell that is otherwise uniform for all three drive concepts, at least in some regions. In other words, the connection regions of the two floor panel assemblies are formed in such a way that they can be connected to a communal front end (front end assembly) and/or a communal rear end, also referred to as rear end (luggage compartment floor assembly) via all three drive concepts. For example, the connection regions of the floor panel assemblies to the bulkhead and the bulkhead itself are formed in the manner described above.

With this concept, it is possible to provide the bodyshells of all motor vehicles of the motor vehicle group according to the invention with a uniform outer skin, i.e. with uniform front side panels (“fenders”), uniform side panels with uniform door cutouts, uniform roof paneling, uniform doors and/or uniform front or rear flaps.

In further detailing, it is possible, in the interests of standardizing the outer skin, to use the fuel filler flap for filling with fuel in the “combustion drive” motor vehicles also in the “electric drive” motor vehicles as a charging flap for an electric plug. Likewise, it is possible to use the loading flap of the “hybrid drive” motor vehicles also for the “electric drive” motor vehicles, as an additional loading flap.

The communality of the bodyshell and/or outer skin is also advantageously continued in the interior trim of the motor vehicles with the three drive concepts. For example, seats, instrument panel support, instrument panel, center console and/or interior trim are communal.

Regardless of the possibly different design of the two luggage compartment floor assemblies, it is possible, for example, to form the trim panels inside the luggage compartment identically, such as the side trim panels.

Furthermore, it is advantageous if electrical components (such as loudspeakers, in particular subwoofers, amplifiers, power distributors, tailgate function module, trailer device) of the motor vehicles of at least two, ideally all three, drive concepts are located in the same way or at least the cable connection points for the individual electrical components are the same.

Preferably, add-on parts to the bodyshell, such as front and/or rear bumpers, have the same interfaces for assembly in the motor vehicles with all three drive concepts. The add-on parts themselves can be geometrically identical or geometrically different. Different external designs of the rear bumpers, for example, come into question for a motor vehicle with “electric drive” because there is no exhaust system with a large-volume rear muffler here. Analogously, the front bumpers can also be formed differently, corresponding to the different cooling air requirements of the motor vehicles of the individual drive concepts. Of course, the bumpers can also be formed differently for design reasons, for example to differentiate externally between the motor vehicles of the individual drive concepts.

Depending on the design of the luggage compartment floor assembly, it is achieved that the luggage compartment of the “hybrid drive” motor vehicles according to the invention is not restricted by the accommodation of a battery or a fuel tank. Thus, even in motor vehicles with “hybrid drive”, a luggage compartment is retained which, in terms of its size, corresponds to the luggage compartment of motor vehicles with “combustion drive”. This means that the “hybrid drive” drive concept can also be implemented in those body variants of motor vehicles which do not have sufficient luggage compartment volume and/or a suitable geometric design of the luggage compartment to accommodate a battery or a fuel tank, such as coupes or convertibles.

The invention further relates to a method for producing a motor vehicle group of one vehicle type, wherein the motor vehicles comprise the three different drive concepts “combustion drive”, “electric drive” and “hybrid drive”. The reduction to two floor panel assemblies, which are embodied as identical parts and differ only in the stiffening of their frame-like structure, reduces the number of deep-drawing dies required. A decisive factor in the method according to the invention is that the two floor panel assemblies correspond with a uniform front body assembly, if necessary also with a uniform luggage compartment floor assembly, at least with luggage compartment floor assemblies which have a connection region which is uniform to the floor panel assemblies. The core concept of the invention is thus to start from the “architecture” of the “electric drive” motor vehicles for the production of both the “hybrid drive” motor vehicles and the “combustion drive” motor vehicles.

Also “within” one of the three drive concepts considered in conjunction with the present invention, different exhaust system components and/or different fuel tanks and/or different electric motors and/or different batteries may be used, depending on the “motorization variant” (for example, gasoline or diesel engine, engine power, battery capacity) and/or drive type (front-wheel drive, all-wheel drive) of the particular motor vehicle. Naturally, the two floor panel assemblies and the two luggage compartment floor assemblies must be designed accordingly for these variants within a drive concept.

The positional designations “front” and “rear”, “top” and “bottom”, “right” and “left”, etc., as well as terms derived therefrom, used in conjunction with the present invention refer to the installation position of the components concerned in the motor vehicle and to the direction of travel of the motor vehicle during forward travel.

The present invention relates to the presentation of an architecture of body-in-white structures for motor vehicles with the three drive concepts “combustion drive”, “electric drive” and “hybrid drive”. The invention also comprises such a motor vehicle group of a vehicle type with three different drive concepts, in which instead of one of the three drive concepts mentioned above, the drive concept “fuel cell” is provided, i.e. an electric motor drive with a power generation unit fed with hydrogen.

Possible exemplary embodiments of motor vehicles of a motor vehicle group of a vehicle type according to the invention, with the drive concepts “electric drive”, “hybrid drive” and “combustion drive”, are shown in the drawing and are explained in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a shows a perspective view of a first floor panel assembly of motor vehicles of a motor vehicle group according to the invention, including front longitudinal members of a front end assembly.

FIG. 1 b shows a view of a second floor panel assembly corresponding to FIG. 1 a.

FIG. 2 a shows a sectional view along the line of section 1-1 in FIG. 1 a.

FIG. 2 b shows a sectional view along the line of section II-II in FIG. 1 b.

FIG. 3 shows a sectional view along the line of section III-III in FIG. 1 a.

FIG. 4 shows a perspective view of the drive train and power supply of a motor vehicle of a motor vehicle group according to the invention, with the “electric drive” drive concept.

FIG. 5 shows a view of a motor vehicle with “combustion drive” corresponding to FIG. 4 .

FIGS. 6 to 8 show views corresponding to FIG. 4 of motor vehicles with “hybrid drive”.

The coordinate system shown in FIGS. 1 a and 1 b with the vehicle longitudinal direction X (corresponding to the direction of travel FR), the vehicle transverse direction Y and the vehicle vertical direction Z is valid for all figures.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1 a and 1 b and FIGS. 2 and 3 show a floor panel assembly B1 a/B1 b. The differences between the two floor panel assemblies B1 a and B1 b are explained in more detail below.

The floor panel assemblies B1 a/B1 b have the following structure in common.

The floor panel assemblies B1 a and B1 b are of frame-like design. They consist of two side longitudinal members ST, a front cross member QT1, a rear cross member QT2, and at least one center cross member QT3. In the present embodiment, two center cross members QT3 are provided. The rear cross member QT2 is covered by an installation space BR. The frame portions bounded by the side longitudinal members ST and the cross members QT1 to QT3 are denoted A. In the present exemplary embodiment, three frame portions A are formed.

The front cross member QT1 has the task of absorbing forces that are transmitted from a front end assembly VO1′ via its front longitudinal members L into the floor panel assembly B1 a/B1 b. As can be seen in particular from the sectional views of FIGS. 2 a and 2 b , the end portions E of the front longitudinal members L are enlarged to ensure large-area force introduction into the front cross member QT1 and/or to compensate for an offset between front longitudinal members L and the front cross member QT1 in the vertical direction Z and/or in the transverse direction Y. In its interior, the front cross member QT1 is stiffened by a reinforcement profile VP1.

The region of the front cross member QT1 is formed as a uniform interface between the floor panel assembly B1 a/B1 b and a uniform front end assembly VO1′ arranged in front of it (see FIGS. 4 to 8 ). This allows the floor panel assembly B1 a and the floor panel assembly B1 b to be connected equally to the front end assembly VO1′.

Similarly, the region of the rear cross member QT2 is formed as a uniform interface between the floor panel assembly B1 a/B1 b and a luggage compartment floor assembly G1 or G2 arranged behind it (see FIGS. 4 to 8 ). This allows the floor panel assembly B1 a and the floor panel assembly B1 b to be equally connected to either the luggage compartment floor assembly G1 or the luggage compartment floor assembly G2.

FIGS. 1 a and 1 b show the schematic cuboid installation space BR in the region of the rear cross member QT2, in which a battery or a portion of a battery, a fuel tank or a portion of a fuel tank and/or, extending further, an electric motor etc. can be arranged.

The side longitudinal members ST are, by their very nature, part of the load-bearing structure of the floor panel assembly B1 a/B1 b and thus of the body-in-white structure of the motor vehicles belonging to the motor vehicle group according to the invention.

FIGS. 1 a, 2 a and 3 illustrate the floor panel assembly B1 a for a motor vehicle with “electric drive”. In the floor panel assembly B1 a, the side longitudinal members ST are formed in such a way that at least one battery 62 for a motor vehicle with “electric drive” extending over almost the entire underside of the floor panel assembly B1 a can be fastened to the underside of a fastening flange F2. The fastening flange F2 extends over the entire length of the side longitudinal member ST. At the level of the fastening flange F2, a reinforcing profile VP2 is provided inside the side longitudinal member ST. In the present embodiment, the reinforcing profile VP2 is formed by a flat-lying two-chamber hollow profile, for example an extruded profile. The side longitudinal members ST are preferably sheet metal components, but can also be formed by extruded profiles depending on the geometry.

The combination of side longitudinal members ST with internal reinforcement profile VP2 and the fastening flange F2 for connecting the battery 62 ensures extremely stable integration of the battery 62 in the body-in-white structure of the motor vehicle. In the event of a lateral collision, the side longitudinal members ST are capable of dissipating a high level of crash energy, resulting in safe protection of the battery 62 “inside” the side longitudinal members ST.

Preferably, the connection between the fastening flange F2 of the side longitudinal members ST and a fastening flange F3 of the battery 62 is made by bolting (bolts S) at a plurality of bolting points V. In addition, the contact surface between the upper side of the fastening flange F3 of the battery 62 and the lower side of the fastening flange F2 of the side longitudinal members ST can be used for bonding.

Analogously, the battery 62 is attached to its front end portion by bolting the front attachment flange F3 of the battery 62 to an attachment flange F1 disposed at the rear of the front cross member QT1, via bolts S at a plurality of bolting points V.

Fastening flanges, not shown, are also provided on the rear cross member QT2.

The fastening flange F1 on the front cross member QT1, the fastening flanges F2 on the longitudinal members ST, and the fastening flange on the rear cross member QT2 form an annular connecting surface running in a horizontal plane. The underside of the middle cross member QT3 also runs in this plane.

This circumferential connection means that the battery 62 is not only securely integrated into the body-in-white structure of the motor vehicle. Rather, the battery 62 with its three-dimensional, trough-shaped housing, including a cover 63 a, is a load-bearing structural component of the body-in-white structure. The plurality of bolts S, possibly in conjunction with circumferential bonding, ensures extremely rigid integration of the battery 62 into the body-in-white structure. Preferably, stiffening elements are provided inside the battery 62 to connect the lid 63 a of the battery 62 to its base 63 b and thus stiffen the housing of the battery 62.

The side longitudinal members ST and the cross members QT1, QT2 and QT3 form a ladder-shaped frame which, in the present embodiment, delimits a total of three frame portions A with two middle cross members QT3. These window-like openings in the frame portions A, without the battery 62 mounted below the frame, are closed by flat closure components VB. This achieves a hermetic separation between the interior and the exterior of the motor vehicle. However, the comparatively thin plate-like closure components VB do not make any appreciable contribution to the stiffening of the individual frame portions A and thus of the entire frame of the floor panel assembly B1 a. Rather, the battery housing 62 has the task of significantly stiffening the frame-shaped floor panel assembly B1 a.

It is advantageous here if the hole patterns for the bolting points V are formed in such a way that they are suitable for fastening different batteries.

FIGS. 1 b and 2 b show the floor panel assembly B1 b for a motor vehicle with a “hybrid drive” or with a “combustion drive”. The floor panel assembly B1 b is formed as an identical part to the floor panel assembly B1 a. The main difference between the two floor panel assemblies B1 a and B1 b is at least one stiffening add-on component ZB, which the floor panel assembly B1 b has as an additional component.

The stiffening add-on component ZB is used to stiffen at least one frame cutout A that is not already stiffened by a battery. In the present embodiment, this is the front frame portion A. This front frame portion A is not occupied by a battery in a motor vehicle with a “hybrid drive”, for example, since batteries for motor vehicles with a “hybrid drive” usually have smaller batteries that do not extend over the entire length of the floor panel assembly B1 b. Motor vehicles with “combustion drive”, by their nature, do not have a battery on the underside of floor panel assembly B1 b that could stiffen one or more frame cutouts A.

In the present exemplary embodiment, a V-shaped stiffening add-on component ZB is provided, which extends between the front cross member QT1 and the front middle cross member QT3. Here, the free end portions of the legs of the stiffening add-on component ZB are fastened via bolts S at the fastening flange F1 of the front cross member QT1. The tip of the V-shaped stiffening add-on component ZB is also fastened to the cross member QT3 by at least one bolt S. For the bolted connection of the stiffening add-on component ZB, at least a part of those bolting points V is used that is used for the bolted connection of the large-area battery 62 in the floor panel assembly B1 a for a motor vehicle with “electric drive”.

The stiffening add-on component ZB is designed as a strut-shaped hollow profile with an approximately rectangular cross section. It has high rigidity and therefore significantly stiffens the front frame portion A.

FIGS. 1 b and 2 b show the stiffening of the front frame portion A as an example. In a corresponding manner, for example, the rear frame cutout A could also be provided with a stiffening add-on component ZB, for example in the case of a motor vehicle with “combustion drive” which has no stiffening battery in this rear region below the floor panel assembly B1 b.

The hole pattern of the bolting points can be matched to the individual batteries to be used across the two floor panel assemblies B1 a and B1 b, thus achieving a high degree of flexibility within the common part concept. However, it is equally possible to provide different batteries within a drive concept that can be connected via a uniform hole pattern for the bolting points V. In particular, the bolting points V along the fastening flange F2 on the side longitudinal members ST of the “hybrid drive” motor vehicles can be used to attach batteries of different sizes.

In addition to the batteries mentioned exclusively so far, fuel tanks, component housings and/or components themselves can also be arranged on the underside of the floor panel assembly B1 b in the case of the motor vehicles with “combustion drive” which do not have large-area batteries. For example, the bolting points V along the fastening flange F2 on the side longitudinal members ST of the “combustion drive” motor vehicles can be used to mount one or more housings. Such housings are able to use the installation space which, as a result of the invention, is also available for accommodating components on motor vehicles with “combustion drive” due to the use of a “raised” floor panel assembly B1 b formed as a common part. Of course, the components can also be arranged directly in the free space on the underside of the floor panel assembly B1 b without a housing.

In addition or as an alternative to the bolting points V with their uniform hole pattern described above, separate fastening devices can be provided for connecting fuel tanks, housings, components and the like, such as fastening brackets.

In summary, the floor panel assembly B1 a is characterized in that all frame portions A are covered by at least one large-area battery 60. What is decisive here is that the at least one battery 60 here stiffens the frames formed by the side longitudinal members ST and the cross members QT1 to QT3 in such a way that the floor panel assembly B1 a achieves sufficient rigidity within the body-in-white structure without any significant further stiffening components. In other words, the battery 60 is part of the supporting structure of the motor vehicle. The “co-supporting” battery 60 eliminates the need for separate stiffening components, with advantages in terms of weight and manufacturing costs for the motor vehicle.

By contrast, at least one frame portion A of the floor panel assembly B1 b is provided with a stiffening add-on component Z intended specifically for this purpose. The stiffening add-on component Z is inserted into the frame formed by the side longitudinal members ST and the cross members QT1 to QT3. Preferably, the connection between the stiffening add-on components Z and the side longitudinal members ST and/or the cross members QT1 to QT3 is made by bolting at least at part of the bolting points V for the battery (batteries) 62 of the first floor panel assembly B1 a.

FIGS. 4 to 8 show the basic structure of the motor vehicles from the motor vehicle group with different drive concepts according to the invention, using perspective views of the chassis and the drive system, omitting the components of the body and the equipment. Each of the motor vehicles according to FIGS. 4 to 8 has a drive train with a front axle VA and a rear axle HA, with front and rear wheels VR and HR, respectively.

The body-in-white structure of the motor vehicles shown in FIGS. 4 to 8 in each case comprises a front end assembly VO1′, a floor panel assembly B1 a or B1 b and a luggage compartment floor assembly G1 or G2. Instead of different luggage compartment floor assemblies G1 and G2, a uniform luggage compartment floor assembly may also be provided. The described three assemblies themselves are not shown in FIGS. 4 to 8 in order to illustrate the components of the chassis and drive system more clearly.

The decisive factor in the interaction of the three assemblies is that the front end assembly VO1′ is formed at its rear end portion and the two floor panel assemblies B1 a and B1 b are formed at their front end portions such that the front end assembly VO1′ is equally connectable to each of the two floor panel assemblies B1 a and B1 b. In addition, the luggage compartment floor assemblies G1 and G2 can be formed at their front end portions to be equally connectable to correspondingly formed uniform rear end portions of the two floor panel assemblies B1 a and B1 b.

The front end assembly VO1′ carries the components of the front axle VA and the steering. The front end assembly VO1′ is equally configured to accommodate an electric motor EV and an internal combustion engine VM (transverse engine) arranged transversely to the direction of travel FR. In addition, the following components, for example, are located on the front end assembly VO1′: components for temperature control of drive units and/or batteries, heating or air conditioning system, electrical and/or electronic components, wiper system, washer fluid reservoir, intake muffler (only for motor vehicles with “combustion drive” and with “hybrid drive”), etc.

The two floor panel assemblies B1 a and B1 b are embodied as frame-like identical parts and differ significantly only in the way the frame portions A are stiffened.

The floor panel assembly B1 a is assigned to motor vehicles with the “electric drive” drive concept. On its underside facing a roadway, it offers sufficient installation space for the arrangement of a battery 62, which occupies almost the entire region under the floor panel assembly B1 a. Instead of one battery 62, two or more batteries 62 can also occupy almost the entire installation space under the floor panel assembly B1 a. The decisive factor here is that the battery 62 (or batteries 62) is (or are) connected to the frame-like floor panel assembly B1 a in such a way that the battery 62 (or batteries 62) alone causes (or cause) the decisive stiffening of the frame portions. In other words, no additional stiffening component is provided on the floor panel assembly B1 a, since the task of stiffening the frame portions is performed exclusively and significantly by the battery 62 (or batteries 62).

The floor panel assembly B1 b is assigned to motor vehicles with the “hybrid drive” or “internal combustion engine” drive concept. On its underside facing a roadway, it provides installation space for the arrangement of a battery 60 a (or several batteries 60 a), which occupies a partial region under the floor panel assembly B1 b. In addition, at least a portion of a fuel tank 50 is disposed on the underside of the floor panel assembly B1 b.

The luggage compartment floor assemblies G1 and G2 cover the region of a rear axle HA and form the underside of a luggage compartment. If different luggage compartment floor assemblies G1 and G2 are provided, the luggage compartment floor assembly G1 runs higher in its front region than the luggage compartment floor assembly G2. The rear region of the luggage compartment floor assembly G1 has a lower portion compared to the luggage compartment floor assembly G2.

The individual motor vehicles according to FIGS. 4 to 8 from a motor vehicle group of one vehicle type according to the invention are described in detail below.

FIG. 4 shows a motor vehicle with “electric drive” from the motor vehicle group according to the invention. It has the abbreviated designation “BEV”. The body-in-white structure of the motor vehicle shown in FIG. 4 is composed of the front end assembly VO1′, the floor panel assembly B1 a, and the luggage compartment floor assembly G1.

In addition to an electric motor EV, the front end assembly VO1′ accommodates other components, such as components for temperature control of the electric motor EV and/or the battery 62, heating or air-conditioning system, electrical and/or electronic components, wiper system, washer fluid reservoir, etc.

The floor panel assembly B1 a accommodates a battery 62 on its underside facing a roadway, which is formed in one piece and extends over almost the entire width of the motor vehicle. The battery 62 may have a bulge 64 in its middle region (drawn with dashed lines), whereby components such as electrical lines and/or coolant lines can be accommodated in this region. If a bulge 64 is provided on the battery 62, the middle cross members QT3 are to be formed in accordance with the bulging shape of the battery 62.

The luggage compartment floor assembly G1 covers an electric motor EV arranged in the region of the rear axle HA. Consequently, the luggage compartment floor assembly G1 offers a luggage compartment volume that, in its front portion, arranged relatively high, is somewhat reduced at the top. In its rear region, however, the luggage compartment floor assembly G1 has a portion arranged relatively low down, which allows a large loading height in the luggage compartment here.

A so-called “road-coupled all-wheel drive” is realized by the electric motor EV for driving the front wheels VR and the electric motor EV for driving the rear wheels HR.

FIG. 5 shows a motor vehicle with “combustion drive” from the motor vehicle group according to the invention. It has the abbreviated designation “ICE”. The body-in-white structure of the motor vehicle shown in FIG. 5 comprises the front end assembly VO1′, the floor panel assembly B1 b and the luggage compartment floor assembly G1 or G2.

The front end assembly VO1′ accommodates an internal combustion engine VM. The internal combustion engine VM is installed in the transverse direction of the motor vehicle and drives the front wheels VR via a transmission and drive shafts. In addition, other components are arranged on the front end assembly VO1′, as mentioned above.

The floor panel assembly B1 b provides an installation space on its underside which is not present in a motor vehicle with a “combustion drive” according to the prior art. At least one housing 60″ for accommodating components of the motor vehicle can be arranged in this installation space. The at least one housing 60″ can also be omitted if there is no need for housing components of the motor vehicle in a housing 60″. In this case, the region below the floor panel assembly B1 b is unused. Alternatively, components of the motor vehicle per se, without a housing 60″, can also be arranged in the region below the floor panel assembly B1 b. A fuel tank 50 is arranged in the region in front of the rear axle HA, below rear seats of the motor vehicle.

The options for using the installation space on the underside of the floor panel assembly B1 b also depend on the two variants of exhaust systems for the internal combustion engine VM shown in FIG. 5 .

In a first embodiment of the motor vehicle as shown in FIG. 5 , the exhaust system ends in the front region of the passenger compartment and has a comparatively short exhaust line AL1 and a rear muffler SD1, the exhaust tailpipe of which is arranged in the region of the side longitudinal member (sill). The elimination of an exhaust system extending to the rear of the vehicle means that the entire width of the region below the floor panel assembly B1 b is available for accommodating components. As shown by way of example in FIG. 5 , a single housing 60″ extending over almost the entire width of the vehicle can thus be arranged.

In a second embodiment of the motor vehicle according to FIG. 5 , the exhaust system is routed to the rear of the motor vehicle, with an exhaust line AL2 shown with dashed lines to a rear muffler SD2 arranged in the rear of the motor vehicle. The installation space occupied by the exhaust line AL2 in the middle of the floor panel assembly B1 b prevents the accommodation of a housing 60″ extending across the width of the vehicle. In this embodiment, for example, two separate housings 60″ can be arranged on the underside of the floor panel assembly B1 b.

As already described in conjunction with FIG. 4 , the luggage compartment floor assembly G1 has a front region arranged relatively high and a rear portion arranged relatively low. Thus, in the motor vehicle shown in FIG. 5 , the luggage compartment floor assembly G1 can only be used in conjunction with the first variant of the exhaust system, without a rear muffler SD2 in the rear of the vehicle. In the second variant of the exhaust system, with a rear muffler SD2 in the rear of the vehicle, the luggage compartment floor assembly G2 is used, which runs higher in its rear region than the luggage compartment floor assembly G1 and can therefore accommodate the rear muffler SD2 on its underside. With its lower front portion, the luggage compartment floor assembly G2 is adapted to the space requirements of “only” the rear axle HA, without an electric motor EH.

FIG. 6 shows a first motor vehicle with “hybrid drive” from the motor vehicle group according to the invention. It has the abbreviated designation “PHEV1/HEV1” (with and without the possibility of charging the battery of the motor vehicle with electrical energy from outside the motor vehicle, respectively). The body-in-white structure of the motor vehicle as shown in FIG. 6 is composed of the front body assembly VO1′, the floor panel assembly B1 b, and the luggage compartment floor assembly G1.

As in the motor vehicle shown in FIG. 4 , the front end assembly VO1′ accommodates an internal combustion engine VM in the form of a transverse engine which drives the front wheels VR. In the present embodiment, the internal combustion engine VM has a “short” exhaust system with an exhaust line AL1 and a rear muffler SD1. Thus, the installation space under the floor panel assembly B1 b is not restricted by a drive shaft to the rear wheels HR or by an exhaust system extending into the rear of the vehicle. Consequently, the entire width of the installation space under the floor panel assembly B1 b can be used for the arrangement of a battery 60 a. However, the battery 60 a does not extend over the entire length of the floor panel assembly B1 b, but only approximately the two rear thirds. A fuel tank 50 is provided in the region in front of the rear axle HA.

The rear wheels HR of the motor vehicle as shown in FIG. 6 are driven by a second electric motor EH arranged in the region of the rear axle HA (“road-coupled all-wheel drive”). The luggage compartment floor assembly G1 provides the installation space required for the electric motor EH below the front portion of the luggage compartment floor assembly G1 with its higher portion at the front.

FIG. 7 shows a second motor vehicle with “hybrid drive” from the motor vehicle group according to the invention. It has the abbreviated designation “PHEV2/HEV2”. The body-in-white structure of the motor vehicle shown in FIG. 7 is composed of the front end assembly VO1′, the floor panel assembly B1 b, and the luggage compartment floor assembly G1 or G2.

The motor vehicle according to FIG. 7 has an electric motor EV in the region of the front axle VA instead of the electric motor EH of the motor vehicle according to FIG. 6. The electric motor EV is preferably integrated in a transmission flanged to the internal combustion engine VM. Thus, both the internal combustion engine VM and the electric motor EV drive the front wheels VR. By omitting the electric motor EH, the luggage compartment floor assembly G2, which runs lower in its front region, can be provided.

Of course, the luggage compartment floor assembly G1 can be used instead.

In principle, instead of the luggage compartment floor assemblies G1 and G2, a third luggage compartment floor assembly optimized for the installation situation in the motor vehicle as shown in FIG. 7 can be used and runs deeper than the end portions of the luggage compartment floor assemblies G1 and G2 at both its front and rear end regions and thus allows a larger luggage compartment volume, although this is associated with additional costs.

In all other respects, the motor vehicle according to FIG. 7 corresponds to the motor vehicle according to FIG. 6 .

In the motor vehicles shown in FIGS. 6 and 7 , the fuel tank 50 and battery 60 are arranged “one behind the other” as viewed in the direction of travel FR. Due to the battery 60 a extending over the entire width of the vehicle, this design is only possible in motor vehicles with a “short” exhaust system.

Alternatively, in the motor vehicles according to FIGS. 6 and 7 , the fuel tank 50 may extend also into a region covered by the rear third of the floor panel assembly B1 b, in interaction with a battery 60 a that uses only the middle third below the floor panel assembly B1 b as installation space. Such a fuel tank 50 is formed in its region below the floor panel assembly B1 b in the manner of a flat plate. Towards the rear, this flat portion of the fuel tank 50 is followed by an upward extension corresponding to the installation space available in front of the rear axle HA and below rear seats of the motor vehicle (as shown in principle in FIGS. 6 and 7). A fuel tank 50 formed in this way is shown in FIG. 8 , but with a width corresponding to only about half the width of the floor panel assembly B1 b.

This embodiment, not shown in FIGS. 6 and 7 , in which the “extended” fuel tank 50 and the battery 60 a are arranged “one behind the other” as viewed in the direction of travel FR, allows a comparatively large fuel tank 50.

FIG. 8 shows a third motor vehicle with “hybrid drive” from the motor vehicle group according to the invention. It has the abbreviated designation “PHEV3/HEV3”. The body-in-white structure of the motor vehicle shown in FIG. 8 is composed of the front body assembly VO1′, the floor panel assembly B1 b, and the luggage compartment floor assembly G1 or G2.

The chassis and drive train of the motor vehicle according to FIG. 8 correspond completely to the motor vehicle according to FIG. 7 .

In contrast to the motor vehicle according to FIG. 7 , in the motor vehicle according to FIG. 8 the battery 60 a and the fuel tank 50 are arranged “side by side” as viewed in the direction of travel FR, i.e. to the right and left of a longitudinal center plane of the floor panel assembly B1 b. Here, both the fuel tank 50 and the battery 60 a extend rearwardly beyond the flat region of the floor panel assembly B1 b into the region of the rear axle HA and below rear seats of the motor vehicle. A significantly larger installation space is available in this rear region. Thus, on the one hand, a larger number of battery compartments can be accommodated here. On the other hand, the greater overall height is particularly advantageous for the fuel tank 50 in terms of surge behavior and ensuring the fuel supply even when the fuel tank 50 is low.

In the “parallel” arrangement of fuel tank 50 and battery 60 a according to FIG. 8 , the fuel tank 50 and battery 60 a preferably occupy only about the rear third or rear half of the longitudinal extent of the floor panel assembly B1 b as installation space. An extension of the fuel tank 50 to the front is opposed by disadvantages due to the low overall height, particularly with regard to the safe utilization of a small residual volume in the fuel tank 50.

With regard to the longitudinal extent of the battery 60 in the direction of the front end portion of the floor panel assembly B1 b, there are in principle no restrictions, in contrast to the disadvantages described for the fuel tank 50. However, it may not be necessary to use a correspondingly large (and thus heavy and expensive) battery in a motor vehicle with the “hybrid drive” drive concept.

The “parallel” arrangement of fuel tank 50 and battery 60 a as shown in FIG. 8 allows the use of an exhaust system leading to the rear of the vehicle, with an exhaust line AL2 running in the region of the center of the vehicle and a rear muffler SD2 arranged in the rear of the motor vehicle. The installation space required by the exhaust line AL2 in the center of the floor panel assembly B1 b is provided by a free space between the fuel tank 50 and the battery 60 a. In this case of a rear muffler SD2 arranged in the rear of the vehicle, only the luggage compartment floor assembly G2 raised in its rear region can be used. Otherwise, the luggage compartment floor assembly G1 can also be used.

Installation space that is available in the “parallel” arrangement of fuel tank 50 and battery 60 a according to FIG. 8 below the front portion of the floor panel assembly B1 b, because no fuel tank 50 and/or no battery 60 a is installed in this front portion, can be used by other installations, such as a housing 60″ for components of the motor vehicle or by components installed “freely” on the underbody.

FIG. 8 shows by way of example with dashed lines how the installation space in front of the “parallel” components constituted by fuel tank 50 and battery 60 a can be used by a housing 60″ and/or by a further battery 60 a. Likewise, this installation space can be occupied by components of the motor vehicle which are arranged directly on the underbody without a housing. The installation space shown in dashed lines can extend over the entire width of the floor panel assembly B1 b (in the case of a “short” exhaust system) or can be divided into two parts in the case of an exhaust system extending into the rear of the vehicle (as shown in FIG. 8 ).

The invention can be summarized as follows: The core concept of the invention is, for a motor vehicle group of one vehicle type with three different drive concepts (“combustion drive”, “electric drive” or “hybrid drive”), to start from the “architecture” of the motor vehicles with “electric drive” for the provision of the motor vehicles of all three drive concepts. Here, regardless of the drive concept, a “raised” floor panel assembly is used in the two variants B1 a and B1 b. The two floor panel assemblies B1 a and B1 b each have a frame-shaped support structure. The first floor panel assembly B1 a is provided for the “electric drive” motor vehicles. Here, the battery 62 is used as a “load-bearing structural component” and plays a major role in stiffening the frame-shaped floor panel assembly B1 a. The floor panel assembly B1 b is provided for the motor vehicles with “hybrid drive” and with “combustion drive”. At least one stiffening add-on component ZB is provided for the floor panel assembly B1 b to give it sufficient structural rigidity.

LIST OF REFERENCE SIGNS

-   -   AL1 exhaust line     -   AL2 exhaust line     -   B1 a floor panel assembly     -   B1 b floor panel assembly     -   BR installation space     -   E end portion     -   EH electric motor     -   EV electric motor     -   F1 fastening flange     -   F2 fastening flange     -   F3 fastening flange     -   FR direction of travel     -   G1 luggage compartment floor assembly     -   G2 luggage compartment floor assembly     -   HA rear axle     -   HR rear wheel     -   L front longitudinal member     -   QT1 front cross member     -   QT2 rear cross member     -   QT3 middle cross member     -   R frame portion     -   s bolt     -   SD1 rear muffler     -   SD2 rear muffler     -   ST side longitudinal member     -   V bolting point     -   VB flat closure component     -   VM internal combustion engine     -   VO1′ front end assembly     -   VP1 reinforcement profile     -   VP2 reinforcement profile     -   VR front wheel     -   X longitudinal direction     -   Y transverse direction     -   Z height direction     -   ZB stiffening add-on component     -   50 fuel tank     -   60″ housing     -   60 a battery     -   62 battery     -   63 a cover     -   63 b base     -   64 bulge 

1.-11. (canceled)
 12. A motor vehicle group of a vehicle type, the group comprising: motor vehicles with three different drive concepts, wherein the three different drive concepts comprise an internal combustion engine (“combustion drive”) or an electric motor (“electric drive”) or a combination of an internal combustion engine and at least one electric motor (“hybrid drive”), wherein a uniform front end assembly with front longitudinal members is provided for all three different drive concepts, two floor panel assemblies are provided, a height of which is identical in an installation position in the motor vehicle, body-in-white structures of the “electric drive” motor vehicles have a first of the two floor panel assemblies, body-in-white structures of the “internal combustion engine” motor vehicles and the “hybrid drive” motor vehicles have a second of the two floor panel assemblies, the motor vehicles with “electric drive” and the motor vehicles with “hybrid drive” have at least one battery arranged over a large area under the floor panel assembly, both of the two floor panel assemblies are of frame-like construction, comprising two side longitudinal members, a front cross member connecting front end portions of the side longitudinal members, a rear cross member connecting rear end regions of the side longitudinal members, and at least one middle cross member connecting the two side longitudinal members, which middle cross member is arranged between the front and rear cross members so as to form at least two frame portions delimited by the side longitudinal members and the cross members, wherein the front cross member and its connecting region with the front longitudinal members are formed in such a way that forces are introduced from the front longitudinal members into the front cross member without further extension of the connecting region on the underside of the floor panel assemblies, in the first floor panel assembly, in the installed position in the motor vehicle, all frame portions are stiffened by the at least one battery, whereas in the second floor panel assembly, at least one frame portion is provided with a stiffening add-on component.
 13. The motor vehicle group according to claim 12, wherein, the stiffening add-on component is connected to the longitudinal and/or transverse members by bolting.
 14. The motor vehicle group according to claim 12, wherein, a flat closure component is positioned in at least one frame portion of the floor panel assemblies.
 15. The motor vehicle group according to claim 12, wherein, in the case of the motor vehicles with the “hybrid drive” and/or with the “electric drive”, the at least one battery is connected to the floor panel assembly by bolting.
 16. The motor vehicle group according to claim 15, wherein, the side longitudinal members and/or the cross members have a hole pattern with a plurality of bolting points which is configured for bolting together different batteries, wherein the bolting points for connecting the different batteries are at least partially identical.
 17. The motor vehicle group according to claim 12, wherein, in the case of the motor vehicles with the “combustion drive” and in the case of the motor vehicles with the “hybrid drive”, at least one fuel tank is provided on the underside of the floor panel assembly.
 18. The motor vehicle group according to claim 12, wherein, in the case of the “hybrid drive” motor vehicles, the fuel tank and the battery extend over virtually the entire width of the floor panel assembly and are arranged one behind the other as viewed in a longitudinal direction of the motor vehicle.
 19. The motor vehicle group according to claim 12, wherein, in the “hybrid drive” motor vehicles, the fuel tank and the battery extend only over part of a width of the floor panel assembly and are arranged side by side as viewed in the longitudinal direction of the motor vehicle.
 20. The motor vehicle group according to claim 19, wherein, a free space for at least one component of an exhaust system is provided between the fuel tank and the battery.
 21. The motor vehicle group according to claim 17, wherein, the fuel tank and/or the battery, as viewed in the longitudinal direction of the motor vehicle, extend into a region below rear seats of the motor vehicle and/or into a region of a rear axle of the motor vehicle and have a greater overall height in this rear region than in their front region.
 22. The motor vehicle group according to claim 18, wherein, the fuel tank and/or the battery, as viewed in the longitudinal direction of the motor vehicle, extend into a region below rear seats of the motor vehicle and/or into a region of a rear axle of the motor vehicle and have a greater overall height in this rear region than in their front region.
 23. The motor vehicle group according to claim 19, wherein, the fuel tank and/or the battery, as viewed in the longitudinal direction of the motor vehicle, extend into a region below rear seats of the motor vehicle and/or into a region of a rear axle of the motor vehicle and have a greater overall height in this rear region than in their front region.
 24. The motor vehicle group according to claim 12, wherein in the case of the motor vehicles with the “combustion drive”, at least one housing and/or a fastening device for at least one component of the motor vehicle is provided on the underside of the floor panel assembly. 